The present invention relates to a new and improved socket for vertically or angularly mounting multi-pin electronic devices relative to a printed circuit board.
In the early application of miniaturized circuitry employing electronic devices such as dual-in-line packaged (DIP) devices and light-emitting diodes (LED), such devices were usually mounted horizontally or flush relative to the printed circuit board. At such time, component density was not considered a critical matter, and thus it was conventional to manufacture such devices so that they were adapted for horizontal mounting by placing the lead pins in rows along opposite edges of the bottom surfaces of the device. With the development of more sophisticated electronics, greater board densities and types of applications have increased and in certain instances it has been found desirable to mount electronic devices in a generally vertical disposition, or at an angled disposition relative to the printed circuit board. As an example, where LED-indicating devices are used in instrumentation circuits, it has been found desirable that in order to conserve panel area, the supporting electronics circuitry should be mounted on a board so as to extend normal to the plane of the board, and with the actual indicator devices being mounted with an indicating space lying normal to the board. It has been known that in order to use currently available LEDs, a narrow second board for carrying the LEDs is attached to the forward edge of the primary circuit board, and is mounted normal thereto. However, in order to establish good plugable interconnection between the circuit boards, the boards must be precisely connected, thereby adding to the overall cost of assembly of the device, in addition to the additional cost associated with providing the second board. Another shortcoming of this mounting arrangement is that in many cases where the primary board layout must be changed, the secondary board must be also redesigned.
In order to overcome the shortcoming of the prior art associated with a multi-circuit board arrangement, it has been known to provide a standard integrated circuit socket with two small printed circuit boards which are secured to the bottom edge of each socket, with the circuit boards being of generally triangular configuration, and maintained in spaced relationship by an insulating spacer bar. The terminal pins in the standard socket are connected, as by crimping or soldering, to the leads provided on the small, triangular printed circuit boards, and at the other end of the leads of the printed circuit board, additional pins are crimped onto the board in order to form terminal pins for connection to the primary printed circuit board. As is readily apparent, the cost associated with the manufacture of the composite standard socket and two small printed circuit boards, as well as interconnection of small pin contacts thereto is relatively expensive, and also requires precision manufacturing in order to prevent shorting of adjacent conductors. Still further, the use of printed circuit boards in conjunction with a socket results in a relatively fragile composite construction, with all of the leads provided on the printed circuit board being exposed to the elements thereby possibly leading to damage through inadvertent striking of the socket during assembly, and also contamination of the socket. Another problem associated with the prior art composite socket and printed circuit board arrangement is that during assembly, such as by soldering of the socket to the primary printed circuit board, there is always the possibility that the solder will flow on the printed circuit board thereby possibly shorting the circuit assembly.
Another form of socket for vertically mounting a multi-pin electronic device comprises the use of a standard socket in conjunction with terminal pins made of sturdy, solid posts of approximately 0.025 square inches, commonly referred to as wire wrap posts. The latter are preferably gold plated, phosphor bronze, and the leads extending from the standard socket are arranged in parallel array and disposed at an angle with respect to the bottom of the socket for achieving the vertical or angular mounting of the LED and the like relative to the printed circuit board. In order to maintain the free ends of the cantilevered terminal pins in spaced relationship, usually an apertured spacer member is provided adjacent the ends of the terminal pins. By virtue of the inherent structural strength of the leads, the resulting socket is structurally stable, however, all of the post portions of the leads extending from the socket are exposed, and thus are also subject to problems by virtue of exposure to the elements. The cost associated with the manufacture of a socket having solid wire wrap posts is relatively expensive, especially in view of the length of the terminal post portions.